Communication devices such as wireless devices may be also known as e.g. user equipments, mobile terminals, wireless terminals and/or mobile stations. A wireless device is enabled to communicate wirelessly in a cellular communications network, wireless communications system, or radio communications system, sometimes also referred to as a cellular radio system or cellular network. The communication may be performed e.g. between two wireless devices, between a wireless device and a regular telephone and/or between a wireless device and a server via a Radio Access Network (RAN) and possibly one or more core networks, comprised within the cellular communications network.
The wireless device may further be referred to as a mobile telephone, cellular telephone, laptop, Personal Digital Assistant (PDA), tablet computer, just to mention some further examples. The wireless device in the present context may be, for example, portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data, via the RAN, with another entity, such as another wireless device or a server.
The cellular communications network covers a geographical area which is divided into cell areas, wherein each cell area being served by a base station, e.g. a Radio Base Station (RBS), which sometimes may be referred to as e.g. “eNB”, “eNodeB”, “NodeB”, “B node”, or BTS (Base Transceiver Station), depending on the technology and terminology used. The base stations may be of different classes such as e.g. macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby also cell size. A cell is the geographical area where radio coverage is provided by the base station at a base station site. By the base station serving a cell is meant that the radio coverage is provided such that one or more wireless devices located in the geographical area where the radio coverage is provided may be served by the base station. One base station may serve one or several cells. Further, each base station may support one or several communication technologies. The base stations communicate over the air interface operating on radio frequencies with the wireless device within range of the base stations.
In some RANs, several base stations may be connected, e.g. by landlines or microwave, to a radio network controller, e.g. a Radio Network Controller (RNC) in Universal Mobile Telecommunications System (UMTS), and/or to each other. The radio network controller, also sometimes termed a Base Station Controller (BSC) e.g. in GSM, may supervise and coordinate various activities of the plural base stations connected thereto. GSM is an abbreviation for Global System for Mobile Communications (originally: Groupe Spécial Mobile). In 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE), base stations, which may be referred to as eNodeBs or eNBs, may be directly connected to one or more core networks.
UMTS is a third generation mobile communication system, which evolved from the GSM, and is intended to provide improved mobile communication services based on Wideband Code Division Multiple Access (WCDMA) access technology. UMTS Terrestrial Radio Access Network (UTRAN) is essentially a radio access network using wideband code division multiple access for wireless devices. High Speed Packet Access (HSPA) is an amalgamation of two mobile telephony protocols, High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA), defined by 3GPP, that extends and improves the performance of existing 3rd generation mobile telecommunication networks utilizing the WCDMA. Moreover, the 3GPP has undertaken to evolve further the UTRAN and GSM based radio access network technologies, for example into evolved UTRAN (E-UTRAN) used in LTE.
In the context of this disclosure, the expression downlink (DL) is used for the transmission direction from the base station to the wireless device, including also the direction from the core network, via the base station, to the wireless device. The expression uplink (UL) is used for the transmission path in the opposite direction i.e. from the wireless device to the base station.
A wireless communications network comprises a transport network that refers to underlying infrastructure responsible for the physical data transport in the wireless communications network. For example, in case of a wireless communications network comprising a core network and a radio access network, the transport network interconnects the core network and the radio access network, parts thereof, and may also include parts that may not belong to neither the core network nor the radio access network since these are typically defined on a logical level, while the transport network is defined on physical level. It is realized that there may be physical entities in the infrastructure that are not defined, and/or are not relevant to discuss as belonging to either one of the core network or the radio access network. In 3GPP networks, Quality-of-Service (QoS) is usually provided and associated with radio bearers of data. When a radio bearer is set up, the QoS parameters, such as Quality of Service Class Indicator (QCI), etc. are indicated to the radio access network, e.g. a scheduler therein, so it will be able to apply specific treatment to data associated with the radio bearer.
When a packet arrives to the wireless network, typically to the core network via a gateway node. from e.g. the Internet, the gateway node determines which bearer the packet belongs to. This is typically done by inspecting a 5-tuple in the packet and trying to match it with Traffic Flow Templates (TFTs). If a match is found, the packet is associated with the bearer and a QCI. The QCI is further translated to a Differentiated Services CodePoint (DSCP) value or Ethernet p-bits that are honoured in the e.g. routers, switches and hubs of the transport network.
However, there are certain cases when the transport network does not provide Quality-of-Service differentiation and the DSCP values and/or/Ethernet p-bits are not honoured. This may happen in cases when an operator of the wireless communications network does not configure QoS in parts of the transport network, such as said routers, switches and hubs, which may be a cumbersome and error-prone process. In some cases the operator might use cheap network elements not supporting sophisticated QoS-differentiation. It may also be cases where the transport network might be out of the operator's control. Also, differentiation of traffic to different bearers is not always done for traffic originating from the Internet since it may require processing that is too high or not possible for other reasons, e.g. technical. As a result a majority of the traffic may be handled by so called best-effort bearers that are not associated with a particular QoS requirements and thus may not be handled accordingly in the transport network. Nevertheless, traffic originating from the Internet typically contains a significant amount of e.g. real-time interactive communications, such as audio, video calls, gaming applications, that would benefit from dedicated treatment and typically need low delays and jitter for good user experience.
With increasing radio capacity and increasing user generated traffic originating from e.g. the Internet it is foreseen that the transport network increasingly will become the weakest link and comprise bottlenecks and thereby experience congestion situations. This makes it of increasing interest to be able to efficiently manage congestion situations in the transport network.
As mentioned above, in some wireless communications networks the transport network does not support QoS specific handling and only implements simple queuing strategies in e.g. switches and routers, without any differentiation of data transport flows. This means that in a congestion situation it is not possible to differentiate data transport flows in the transport network and thus not possible to provide prioritized treatment although this would be desirable. In such situation the end-to-end QoS will be determined by the weakest link involved. In such cases, and also in cases of transport networks that are QoS-unaware, only best effort service class may be offered.